Source : Webster's Revised Unabridged Dictionary (1913)

Italic \I*tal"ic\, n.; pl. {Italics}. (Print.)
   An Italic letter, character, or type (see {Italic}, a., 2.);
   -- often in the plural; as, the Italics are the author's.
   Italic letters are used to distinguish words for emphasis,
   importance, antithesis, etc. Also, collectively, Italic
   letters.